That's not necessarily what retirement means, and it's not what he indicated in the story.
> I don’t have any specific plans for what I’ll be doing next, other than not doing any kind of software for a while. I’m itching to create more tangible things, especially art and music, so I’ll likely put a lot of effort in to exploring those things more.
Nothing in there says the art/music can't make any money, nor does he rule out software again in the future. As he notes, "I absolutely love starting things..."
Retirement frequently means something different for a 30-something CEO who just exited ("I don't have to work") versus a 70-something year old ("I'm done working").